Dust flux, Vostok ice core

Two dimensional phase space reconstruction of dust flux from the Vostok core over the period 186-4 ka using the time derivative method. Dust flux on the x-axis, rate of change is on the y-axis. From Gipp (2001).

Saturday, February 20, 2016

Vignettes of water in China

Whistling up the line from Guangzhou back to Zhengzhou at 300 km. The landscape blurs by, first high hills and flooded paddies, people out in the fields planting and tilling (enjoy your winter, Canada!). The hills are the bright red and orange of tropical soils, deeply incised by rushing waters. After a time, the hills become strange and solitary, and then we are north of Changsha, and the land flattens out. The last few hours are spent over a plain as flat as anything in the prairies. Occasionally there is a little stream is guided by a high levee over a plain that would otherwise lie below the water. But as we go farther north, the streams and rivers are cut into the plain, and the levees are gone.

In the south, the planting is well underway. Not so in the north, where two weeks ago, the fields were still dusted in snow.

When I moved to China 18 months ago, I was in pretty bad shape. I had reached the terminal phase of a long-term illness. One reason I moved to China was because the soil mineralogy was favourable for my condition. Other places I could have gone to were India and Egypt. Egypt I rejected for political reasons. India I rejected because I feared I would melt. Plus the culture of China was more favourable for me, apart from the little problem of not being able to speak much Chinese.

Within two months of arriving, my energy levels had improved, and I had noticed a tremendous improvement in my fingernails. That may sound trivial, but having bad nails is a sign of mineral problems. Mine were weirdly thin, they would fracture along crescents, and were deformed. After a few months in China, they looked normal.

The soils of China and India (and the Nile delta) are extremely mineral rich. This explains why for much of recorded history, the population of China and India has been so large.

The richness has to do with water.

A search of "Geography is not destiny" on Google shows this is a quote that has been used many times in many situations. However, it seems that "geography is destiny" also appears as a quote in many works. This being the World Complex, we will say that geology is destiny. In this case, the assembly of many subcontinents into one large continent (Asia), combined with the geologically recent rise of the Himalayas, results in the most powerful monsoonal climate pounding against a rapidly rising mass of rock. The end result is torrents of water rushing out of the mountains, flooding both China and India with mineral-loaded water--the minerals being eroded rock dust from the mountains. Thus every year the soils in these countries are recharged not only with water, but with minerals.

Over time, the Chinese (and the Indians) learned exactly what to do with water. Their agricultural system depended on the flooding. The Han people spread out over the plains, and the minority people were left to struggle on the flanks of mountains, and in other areas that were too marginal to be of interest to the dominant Han.

What was their answer?

Terraces. Lots and lots of terraces. These are Longji terraces, a couple of hours drive from Guilin.

These are a bitch to water. If you are lucky, there may be a stream flowing down from the top of the hill. Some of these have to be watered by pumping water up the hill one terrace at a time.

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Water is central to Chinese culture--so much so that the demands of building may be set aside to meet the requirements of water. The stone depicted below was recovered about five years ago in Guangzhou during the dredging of a waterway--it is a governmental proclamation ordering that no building take place on an elevated plain that was of great importance to the health of the surrounding waterways.

The proclamation, dated April 23, 1883, prohibits construction on the plain to prevent damage to wells and streams. It is written from the standpoint that the area was important to the health of local streams because construction would be a bad omen--in other words, a supernatural explanation was offered. But I can't help wondering if someone in the local government had a notion about groundwater and recharge zones, but knew it was pointless explaining it that way to local farmers.

Interestingly, the proclamation was declared in response to a suit by local farmers against a local man who had bought land on the high plain, and who planned to build a large mansion there. So even the folk people may have had some idea of the connection between the recharge area and the surrounding streams.